Exercise device



FIG. 1 is a perspective view of an exercise device,

FIG. 2 is a side view of the exercise device shown in FIG. 1,

FIG. 3 is a top view of the exercise device shown in FIG. 1; and,

FIG. 4 is a front view of the exercise device shown in FIG. 1. 

The ornamental design for an exercise device, as shown and described. 